That is exactly what I'm building pond for myself: one store for all my sessions, Codex and Claude Code both and a bunch of others including OpenClaw, and my agents can access it over MCP. It also happens really often that when my agents cannot find something, they just call pond search themselves. Faster that way. Whenever I need a session from a while ago now, I just know it's in pond. Repo, if you'd be willing to give it a try: github.com/tenequm/pond